For example, we normally predicate truth of propositional entities like assertions or beliefs. But we can grasp a proposition as potentially true or false only to the extent that we can understand how to use it to uncover or make salient a fact or state of affairs. So we could say that the being of truth resides in uncovering. Thus Heidegger takes uncovering in a broad sense – lifting into salience – to be the ontological function of truth. He then applies the term in a broad sense to anything that uncovers. So, for instance, if I drive a nail into a board, I am uncovering the way a hammer is used. In this broad sense, my action, for Heidegger, is true – in hammering, I lift into salience what a hammer is and how it is used. Or if a building like a medieval cathedral supports the faithful in their efforts to inhabit a world opened up by God's grace, the cathedral is also true in the ontologically broad sense – it works by lifting into salience what is essential or most important about such a world, and supporting the disclosive practices of that world's inhabitants.